Chinese internet giant Baidu has hired top computer scientist Andrew Ng - once head of Google Brain, the American firm's "deep learning" project.

The recruitment of Ng, a pioneer in artificial intelligence, shows the big ambitions of China's leading technology companies.

Baidu has appointed Ng as chief scientist to head an expanded research operation in Beijing and its new labs in San Francisco. Ng will also lead the development of artificial intelligence.

Deep learning, regarded as the next big development in computer intelligence, refers to research that enables machines to simulate brain functions and process huge amounts of data.

He's highly intelligent ... a top researcher in machine learning

Professor Pong Ting-chuen

Analysts believe the major signing of such a big name will make it easier for Baidu to compete and attract further talent to take on Western technology giants in Silicon Valley as they poach top talent from American rivals.

Ng, a long-time Stanford researcher whose family is from Hong Kong, was a key member of Google's secretive project X - the same division that developed Google Glass and driverless car technology. He left Google last year to start his own company, Coursera, an online education start-up.

Professor Pong Ting-chuen, provost of teaching innovation and e-Learning at the Hong Kong University of Science and Technology, praised Baidu's hiring of Ng.

"I first met Andrew when we talked about a partnership between HKUST and Coursera," Pong said. "He's a highly intelligent and technical guy. No doubt, he is one of the top researchers in machine learning; in particular his work in deep learning attracts a lot of attention."

During his time at Google developing artificial intelligence, Ng trained an army of computers to mimic human brains and recognise a cat by analysing thousands of YouTube videos.

Pong said the advancement of deep learning - and extracting data to get knowledge - would reshape the use of computers. "It is an area people think will advance the intelligence of the computer," he said. "A lot of work that couldn't be done in the past can now be realised."

Ng confirmed his departure on his company blog.

Baidu's chairman and chief executive, Robin Li, said Ng was the "ideal individual to lead our research efforts as we enter an era where AI plays an increasingly pronounced role".